Flying Horse 48cc/66cc/80cc Motorized Bicycle Engine 40mm Intake Manifold &ndash; Gas Bike Manifold (40mm) The 40mm Intake Manifold is for 2-stroke bicycle engine kits, both for 66/80cc's and 48cc's Manifold sizing is based on the distance between the center of each intake stud; 40mm for this manifold Compatible with most carburetors out there except for CNS High Performance Carburetors The aluminum these are made from is thick enough and strong enough to be tapped for a Boost bottle or NOS without damaging its integrity